One evening, I invite my coworker Maki home for drinks. My wife Rei dislikes the way he constantly stares at her breasts and keeps her distance from our conversation. Apparently aware of the tension, Maki gives us a ticket to a popular spa as an apology. Rei is reluctant, but I persuade her to go because it is free. The spa, however, is a trap arranged by Maki and its staff, and I end up witnessing my wife’s humiliating sexual behavior through a magic mirror.